Electrode for the electric arc



Sept. 2, 1930. E. K. DEWEY ismscwaona FOR THE ELECTRIC ARC 01 iginal Filed July 6, 1925 SHELL CORE W -e Wm F vs m E His Attorney Patented Sept. 2, 1930 UNITED STATES PATENT OFFICE ERNEST K. DEWEY, F SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY,

A. CORPORATION OF NEW YORK ELECTRODE FOR THE ELECTRIC ARC Application filed July 6,

My invention relates to electrodes for the electric arc, and more in articular to electrodes for the so-called high intensity type of arc. Heretofore, cored, high intensity electrodes have been made adapted to carry a load of .150 ampcres at a voltage as high as 78 volts; Electrodes of this type consist 0 'a shell about 16 mm. in diameterand 8 mm.

core. This'shell is composed of calcified coke 10 and lamp black and anecessary binder such as coal tar. This electrode is provided with a core which is composed lamp black and a mineral salt.

It is the objectof my invention to provide an electrode which will permit the use of a current as high as 250 amperes or over an which will give a steady intense light, ossibly 100% stronger than .when stan ard electrodes are used.

In order to accomplish the foregoing Iuse electrodes of the cored type as shown in elevation and partly in section in the accompanying drawing. The details and ingredients of the electrode of the invention are as follows:

In place of the usual core I provide an elec-' trode, the core of which contains a mixture of cerium oxide, titanium carbide, boric oxide, and carbon, and a binder such as tar and the ratio of the diameters of the shell and core are. 2 to l-preferably.

I find that excellent results are obtained' by using the following proportions of the 1ngredients for the core: cerium oxide 72%,

titanium carbide 8% boric oxide 1% and carbon 19%. This car on may be in the form of fired lampblack. The binder may be as high as 25% of the total weight of the ingredients of the core, and even as high as 30%.

40 By using electrodes of this sort in an arc lamp and in which the positive electrode is 16 mm.

in diameter, and the core 8 mm. in diameter, the arc maybe operated with a current flow above 150 amperes, and even as high as.250

amperes, thereby increasing the amount of light very materially, even as high as 100% over that obtained when the electrodes of the prior art are used. Notwithstanding the great volume of current, the arc, when using electrodes of my invention burns quietly and of .a mixture of d shell, said shell having 1925, Serial lid-41,885. Renewed July 1, 1930.

steadily, the are being free from any objectionable smoking, as is the case when electrodes of other types are used with such high current densities.

While I have described n1 connection with certain speci invention in c proportlons,

f it will be understood that I do not WlSh to be limited to the specific proportions named, inasmuch as, in view of the disclosure, such proportions may a ing from the spirit of theinvention or from the scope of the claims contained herein.

What I claim as new and desire to secure by Letters Patent of the United States is: 1. An electrode for an are having a carbon a core consisting of a mixture of a cerium oxide and a boron oxide, together with .carbon and titanium carbide. 2. An electrode for an are having a carbon shell, said shell having a core consisting of a mixture of boric oxide and carbon, together with titanium carbide and cerium-oxide.

3. An electrode for an are having a carbon shell, said shell having a core consisting of be varied without depart- 4. An electrode for an are having a carbon shell, said shell of-cerium oxide 72%, titanium carbide 8%, boric oxide 1%, and carbon 19%, and a binder for the ingredients of the core, said binder being 20% by weight of the ingredients.

5. An electrode for an are having a shell, a core within said shell, said core consisting of a mixture of comparatively large proportions of both a cerium oxide and carbon, a

1 small proportion of a boron oxide, and titanium carbide, the proportion of the titanium carbide being much larger than that of the boron compound and much smaller than that of the cerium oxide.

In witness whereof, I have hereunto set my hand this 3rd day of Jul. 1925.

' ERNE T K. DEWEY.

having a core consisting 

